Detinning tin-scrap.



GOLUSCHMIDT n WEBER DETINNING TIN SCRAP.

APPLICATION FILED AUG. I 1906.

Patented (Ict. 2b, 1915.-

2 SHEETS-SHEET I.

. WEBER.

DETINNING TIN SCRAP APPucATloN man Aue.1,1soe

K. GOLDSCHMIDT QJ Patented Det. 26,1915.

2 SHEETS-SHEET 2.

` Inn/Toffs` WITNESS KARL GOLlDSCMIDT AND JOSEF WEBER, F ESSENON-TIIE-RUHR, GERMANY, ASSIGN- ORS, BY MESNE ASSIGNMENTS, TO GOLDSCHMIJDT DETINN IN Gr COMPANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

permutas Tru-sonar.

Specification of Letters Patent.

Application filed August 1, 1906. Serial No. 328,783.

To all whom t may concern Be it known that we, KARL GoLDsoHMIDT and Josur WEBER, subjects of the'King of 1 one, the temperature rising to such an extent L immediate equalization of the .temperature the temperature, though Prussia, German Emperor, and residents of Essen0n'-tlie-R-11hr, Germany, have invented certain. new and useful Improvements in Processes of Detinning Tin-Scrap, of which the following is a specification.

All processes of detinning tin clippings, tin cans or "other tin bearing material by means o c rin that have heretofore been practised, whether they.; have been carried -out with chlorin alone orf by chlorin diluted with an inert. gas or by the use of chlorin inthe presence of an anhydrous liquid present the great olrawback thatI at the points where the reaction takes'place, that is, where the stannie chlorid is formed, an excessive temperature is developed, this increase in temperature, however, being an irregular at certain points in the vessel as to enable the chlorin to affect the iron injuriously, while at other points in the vessel a much lower temperature prevails.

In order to produce a detinned iron that .has not been unduly attacked by the chlorin,

and in order also that the process as a whole may be carried out in the shortest period of time, it is of the utmost importance that varying from time to time during the detinning period, shall at any ygiven time be as nearly uniform as possible throughout all parts of the apparatusin which the detinning is taking place. This is one of the chief objecits of our present invention, and it may be ,-ttained by imparting to the Iparticles o, agent, such a's chlorin, whether .it is used alone or in combination with an inert fluid, in gaseous or liquid form, such a stirring motion as will result in a thorough commingling of the particles in the vessel. By imparting a proper stirring or whirling motion to the Jfluids or gases in the vessel an in the various parts ofthe apparatus may be obtained and constantly maintained throughout the detinning operation.` Such a stirring Aor u 'hirling motion can be pro'- duced by dividing the .apparatus or vessel in which the detinning is to take place into two or more chambers, la's by means of one' pipe outside of the the reacting.

or more partitions, through which chambers the iuids may be constantly circulated 'in any suitable manner,v means .of a pump by which they may be drawn or forced through each chamber, and 1f desired, constantly circulated from .one chamber into another and back again into that from which they Were Withdrawn. In this method the stirring or circulating action is produced and takes place entirely within the apparatus in which the takes place. Another method which may be employed consists in drawing 0E the fluids from one side of the vessel through a same and returning'said iiuids to the vessel at the other side of the apparatus, preferably after the gases have been considerably cooled. The equalization of temperature produced by such an agitation or commingling of the gasesgin the vessel as has just been' described is not, however, the only result of the present invention, nor is it the only feature thereof that is: of value in the art of detinning.

An important feature of the invention, which extends beyond the mere equalization of the temperature in the different lparts of the apparatus, is the rapid cooling of the as for example, by

detinning contents of the apparatus, particularly of the reacting agents, contained therein, which cooling is a result of the agitation and commingllng of the gases and liquids in contact with ,a heat-absorbing medium or surface, the best results being obtained. inv the detinning process when said fluids are circu- .that in detinning on a large scale the use of a water' jacket alone does not produce the desired cooling effect. lVe have found that unless the getically' agitatedgor circulated in contact with a heat-absorbing medium, it is diihcult gases within the vessel are enerf to reduce the temperature 'of' the vessel to the proper extent, asgases 1n a state of rest and in large 4masses are such poorconductors of heat thatwhen `acted upon in .such a statey by acooling agent, such for example ascold Water running over the surface of the apparatus, the reduction ofthe temperature within the apparatus is very slow. yBy keeping the gases' constantly in motion and circulating them through the vessel in such a manner as to bring fresh particles constantly n into contact with the heat-absorbing medium or surface, a very rapid cooling of the gases and other contents of the apparatus results.

This method involves also the additional rand great advantage of permitting the thorough detinnin of-the scra in a much shorter time than has heretofore been required, and hence a very great economy 1n `the yoperation of the plant.V Itis important to bear in mind that as in this process gases dinarily be filled with about fourteen tons of material containing about 2.35% of tin, andthe vessel will contain about 330 kilograms of tin. As'the heat of combustion of one kilogram of tin in chlorin is 1078 cal0.

ries, there will be developed in the vessel an amount of heat represented by 355,740 calories.. Now, if we assume that an increase of 400 C. in temperature takes place in the fourteen tons of scrap introduced into the apparatus and in the metal of the apparatus itself, which, if of the above dimensions woiild weigh' about six tons, making a total of twenty tons ofiron, the specilic heat of which is .105, then this twenty tons of iron will absorb only 84,000 calories of thetotal heat developed. There would thus remain 271,740 calories which would ordiv naril)Y escape into the workroom by radia- Hence, about thirty ltion from thesurface of the apparatus.

Now, one square meter of iron will set free at ka difference of temperatures of 40 C. about 240 calories perhour by radiation, so

that the apparatus above described, which has a surface of thirty-eight square meters, would set free 0120 calories per hour. .'orking hours would be required to carry out the process if radiation by the apparatus alone were depended upon to dissipate the heat" developed.

The course ofthe operation will not bel much quicker` eveny if the detinning vessel is cooled with water from the outside, for this Wi-ll only serve to cool thosepaiticles of gas which are nearest to the inside wall of the apparatus, and hence the equalization of the temperature within the apparatus will still be very slow.

The cooling of the gases will be much more rapid if those gases are agitated energetically, as'before described. If this is done, and the vessel is simultaneously cooled bythe outside application of water, the whole process, as has been demonstrated in practice, can be completed in twelve hours instead of thirty. Thelsame result is secured .by circulating the gases through an air cooler with a large surface, say one hundred square meters, instead of circugiating water around the outside of the apparatus/ In addition to energetically agitating the gases or qausing them to circulate through the apparatus, a further means that may be employed 'for equalizing and reducing the temperature is the introduction of an anhydrous fluid, for example, liquid perchlorid of tin, into the apparatus and into contact with the gases therein.- This liquid pci-chlorid of tin may be introduced at the top of the vessel and caused to How down, preferably in ine streams, through the gases to the bottom of the vessel, where it may be collected. IVlien introduced in this manner it will circulate oppositely to the gases to be cooled. By employing such an anhydrous heat-absorbing fiuid as an auxiliary, the circiilating gases readily give up their heatto such anhydrous liquid as well as to the metal of the vessel itself. Thus the'anhydrous liquid presents additional heat-absorbing surfaces to the chlorin gas, which, however, must be constantly in a state of agitation and energetically circulating throughout the apparatus, in order to produce the best results. The most intimate contact between the various particles of the gas and the particles of the anhydrous liquid is obtained by circulating the anhydrous fluid vthrough the vessel in line streams, and preferably in a direction opposite to that in which the gases arc moving. An anhydrous heat-absorbing liquid, such as that before described and which may be circulated through the apparatus simultaneously with thefchlorin gas, presents the great advantage that it can be more easily cooled, and.A

afterward possesses greater lieat-i'ibsorbiiig power, than an equal volume of ga's.

In the drawings we have illustrated different types of apparatus for carrying out our improved process.

Figure l illustrates a detinning apparatus divided into two compartments by a partition, the view `being a vertical section taken in line A-A, Fig. 2; Fig. 2 is a horizontal section of the same, taken in line Bv-B, Fig. l; Fig. 3 illustrates in the same manner as in Fig. 1 a similar apparatus showing a modification of `the invention; and Figal is a similar .vicwillustrating said apparatus further modified.

In Figs.l l and 2 the. dctinuu'ig vessel is divided by a partition (Z into two chambers (l, and l), from the* first of which gaseslowbottom thereof, and flow into the chamber andfrom which in turn they, are returned 4to the chamber o, at the upward through said chamber' c fThis circulation of the raises is constantly maintained in any suitable mannenas for'eiample, by'means of pumps o and o. vAt the outsidejof the aprol paratus cold waterf is preferably kept constantly circulating by meansnf1 a spray or other device s over the outer s ell or mantle m in order "to absorb as much as possible of the heat ofthe shell of the apparatus and of the gases in Contact with, or lying close to the -inner surface thereofbe noted that thefmorerapidthe circulation of the gases within the vessel, the greater will be the'cooling 'elfect of the metallic mantle of the apparatus on sa'id' gases.

ln Fig. 3, instead of circula-ting the gases' from one chamber'to another of the detin ning vessel, a pipe r is placed outside the apy paiatus, and the gases are withdrawn from the apparatus-at one vside through said'l pipe and returned'. to the apparatus at the yother side thereof. In this :case also a pump is preferably employedfor the purpose of rapidly circulatingthe gases through ratus and the pipe r.

In order ,to obtain Kthe best results a 'System of cooling pipes, such as are shown at in Fig. 4, may beemployed to sub-divide the mass or stream and increase the superficial area exposed to the cooling' action. These pipes maybe used either as ain auxiliary in the cooling of the gases, used alone, that is, Without thesimultaneous the appa* application' of water` to the outside or 4mantle of the vessel.

ln carrying outjourimproved process We proceed as follows: The apparatus vis :filled with tin scrap, usually .compressed scrap, preferably in bundles, carried in scrap-containers such as c, and the apparatus is then closed by suitable means, including a cover n, and chlorin introduced under a pressure which may be increased during the detinning, so that the temperature is kept at the desired point. During the introduction of this chlorin gas, which is suitably controlled to produce thedesired result, an energetic.

agitation and circulation ot' the gas, or of the chlorin gas and the inert gas or gases used in connection therewith, should be begun. Simultaneously'th'e circulation of the anhydrousy heat-absorbingf `fluid, such as Y liquid lpcl'lilorid oftiinzmay' be edected, in

A order that it may absorb the.' heatof the chlorin gas'w'hile such 'gas is-in'j'rapid motion, this li'riuidbeing introduced for ,example at p. By carrying out the process in this man- 'ner substantial` equality of temperature vthroughoutthe iessel is assured, and an energetic circulation of the gases along the cooling surfaces presented by the Walls of It will' or may 'bevessel, andjhence in the carrying out of the whole process in an efficient and economical manner.-

It will be found advantageous not to let the stamiic chlorid formed by the process pass through the apparatus With Ithe gases used to bring about the reaction, but to let it'drip down, since if it Were to pass through the pump the latter would be burdened unnecessarily. This stannic chlorid may be removed by means of a special pump. It may be drawn off during the operation.y

lt should vb e mentioned that it is left entirely to the discretion of the operator whether to use the special cooling means hereinbefore described 0r to dispense With them and make use only of natural radiation to cool the apparatus and its contents. In every case, however, the energetic agitation or circulation of the gases ymust be effected in order to avoid a dangerous increase oi temperature in various parts of the apparatus and prevent injury of the product.

By the term chlorin, as used in the claims, is meant not only chlorin gas alone, but any mixture or combination of chlorin with inert gases or inert liquids, provided that such mixture or combination contains chlorin in suiiicient quantity tofact as a detinining reagent.

1. The process of detiii'nn'gv tin-scrap which consists in introducing chlorin into a closed apparatus containing fthe'scrap and imparting to the body oii'gases confined in the apparatus an energetic y whereby the temperature is substantially equalized throughout the scrap.

closed apparatus containing the scrap and imparting to the body of gases 'confined in substantially equalize the .throughout the scrap, the temperature being maintained :at a point below that/rat which attacked:

loo

stirring motion,

2. The process of 'detinning tin-scrap which consists 1n mtroduclng chlorin luto a which consists in introducing chlorin into a closed apparatus containing the scrap, 11nparting to the body of gases Within the apparatus a stirring motion suiicient to substantially equalize the temperature throughout the scrap, and circulatingthe gases in contact with a heat-absorbing surface,

ira

whereby the temperature of the. contents of l' iti) ironils n ,fw 11a' 3. he process of detinnmg` tin-scrap,

-geticfstirring'motion, whereby the temperature is substantially equalized throughout the scrap.

i The process 0f detinning compressed tin #seraJ which consists in introducing D chlorin into ai closed apparatus containing the compressed scrap and imparting tothe body ofgases confined in the` apparatus a stirring motion suliicient to substantially equalize the temperature throughout the 1.scrap, the temperature being maintained at a point below that at which iron is attacked. -1;6.1.'l`he process of detinning compressed tin-scrap which consists in introducing chlorin into-a closed apparatus containing -11 the compressed scrap, imparting to the body increasing pressure into a closed apparatus ofgases within the apparatus a stirring motion lsufficient to substantially equalize the ten'iperature throughout the scrap, and circulating the gases in contact with a heat-absorbing surface, whereby the temperature of the contents ofthe tank is maintained at the desired degree.

i. The process of -detinning tin scrap which consists in introducing chlorin under containing the scrap and imparting to the body-of gases confined in the apparatus an energetic stirring motion, whereby the temperature is substantially equalized throughout the scrap.

8;- The process of detinning tinscrap which consists in introducing chlorin into a closed apparatus containing the mass of scrap, imparting to the body of gases within :the apparatus a-stirring motion sufficient to substantially equalize the temperature throughout the scrap, .cooling the chlorin that passes out of the scrap and ire-introducing said cooled chlorin into said mass.

:gases within the chamber an energetic stirring motion, and, circulating the gases in contact with the cooled wallsl of the chamber whereby the temperature of the contents of the tank is substantially equalized and main'- :flf tained at the desired degree,l A

10..The process of detinning tin-scrap which consists in circulating chlorin through a. mass of tin-scrap whereby the temperature-is maintained approximately uniform 5in all parts of the mass and simultaneously circulating a heat-absorbing fluid in contact with said gas. V

11. The process df detinning tin-scrap which consistsin circulating'chlorin through a mass of tin-scrap whereby the teniperatu is maintained approximately uniform in :lil parts of the mass and ,simultaneously circulating a heat-absorbing anhydrous liquid in contact with said gas.

12. The process of detinning tin-scrap which consists in" circulating chlorin through a mass of tin-scrap whereby the temperature is maintained approximately uniform in all parts of the mass and simultaneously circulating a heat-absorbing liquid in contact with said gas and in a' direction opposite to ,theiow of said gas.

.13. The process of detinning tin-scrap which consists in circulating chlorin through a mass 'of tin-scrap whereby the temperature is maintained approximately uniform in all parts of the'mass and simultaneously circulating streams of perchlorid of tin in contact with said gas.

14. The process of detinniiig tin-scrap which consist-sin circulating chlorin and an inert gas through a mass of tin-scrap whereby the temperature is maintained approximately uniform in all parts of the mass and simultaneously circulating' a. heat-absorbing Huid 'in contact with said chlorin.

15. The process of detinning tin-scrap which consists in circulating chlorin and an inert gas through a mass of'tin-scrap whereby the temperature is maintained. approximately uniform in all parts of the mass and simultaneously circulating a heat-absorbing anhydrous liquidY in contact with said chlorin.

16. The process of detinning tin-scrap which consists in circulating chlorin and an inert gas through a mass of tin-scrap whereby tlie temperature is maintained approximately uniform in all parts of the mass and I' simultaneously circulating fine streams of a heat-absorbing anhydrous liquid through the chlorin in a direction opposite to the flow of said chlorin.

In witness whereof we have hereunto set our hands 1n the presence of two witnesses.

Dit KARL GoLDscHiuiDT. DR. Josnr WEBER. lVitnesses I WILLIAM EssENwniN, ALFR. POHLMEYER. 

